1. Field of the Invention
Aspects of the present invention relate to an image forming apparatus, and more particularly, to a inkjet image forming apparatus including a printhead having a length corresponding to the width of a printing medium, and a spitting method for the inkjet image forming apparatus.
2. Description of the Related Art
An inkjet image forming apparatus ejects ink onto a printing medium, to form an image. Inkjet image forming apparatuses are classified into shuttle-type inkjet image forming apparatuses, and line-type inkjet image forming apparatuses, according to the printing method. The shuttle-type inkjet image forming apparatus prints an image using a printhead that is shuttled in a direction perpendicular to a transfer path of a printing medium. The line-type inkjet image forming apparatus prints an image using a printhead that includes a nozzle unit having nozzles arranged across a transfer path of a printing medium.
Generally, in a printhead, a thermal element or a piezoelectric element is used to eject ink. High resolution print heads are manufactured using a semiconductor manufacturing process (e.g., etching, deposition or sputtering). In printheads, ink is ejected from a nozzle unit formed in the printhead, onto a printing medium, to form an image. Over time, ink can build up on a surface of the nozzle unit and/or in nozzles of the nozzle unit, interfering with the ejection of ink droplets, thereby reducing printing quality. In order to prevent such problems, a maintenance operation is performed to clean the nozzle unit. The maintenance operation includes wiping and spitting operations, or the like. The wiping involves wiping away residual ink left on the nozzle unit. The spitting involves the ejection of ink, after a printing operation has been performed. In addition, to effectively remove residual ink left in/on the nozzles, nozzles are cleaned with a cleaning solution, using ultrasonic waves.
The printhead of the line-type inkjet image forming apparatus includes a nozzle unit to eject ink, having a length corresponding to the width of a printing medium. When the nozzle unit is wiped, ink wiped from a nozzle row may contaminate other nozzle rows. That is, since the printhead, of the line-type inkjet image forming apparatus, has a long length, waste ink wiped from one nozzle row may contaminate other adjacent nozzle rows.